(a-b)—=a2-2ab+b2
We know the identity (a-b)2=a2-2ab+b2
(a-b)2=(a-b)(a-b)=a2-ab-ba+b2(aftermultiplyingthebrackets)=a2-ab-ab+b2(ab=ba)=a2-2ab+b2
Hence, the answer of the blank is (a-b).
Which of the following is correct? a) (a−b)2=a2+2ab−b2 b) (a−b)2=a2−2ab+b2 c) (a−b)2=a2−b2 d) (a+b)2=a2+2ab−b2
If a + b + c = 2s, then prove the following identities
(a) s2 + (s − a)2 + (s − b)2 + (s − c)2 = a2 + b2 + c2
(b) a2 + b2 − c2 + 2ab = 4s (s − c)
(c) c2 + a2 − b2 + 2ca = 4s (s − b)
(d) a2 − b2 − c2 + 2ab = 4(s − b) (s − c)
(e) (2bc + a2 − b2 − c2) (2bc − a2 + b2 + c2) = 16s (s − a) (s − b) (s − c)
(f)
